2,509 research outputs found
Synthesis of Highly Stable 1,3-Diaryl-1H-1,2,3-triazol-5-ylidenes and Their Applications in Ruthenium-Catalyzed Olefin Metathesis
The formal cycloaddition between 1,3-diaza-2-azoniaallene salts and alkynes or alkyne equivalents provides an efficient synthesis of 1,3-diaryl-1H-1,2,3-triazolium salts, the direct precursors of 1,2,3-triazol-5-ylidenes. These N,N-diarylated mesoionic carbenes (MICs) exhibit enhanced stability in comparison to their alkylated counterparts. Experimental and computational results confirm that these MICs act as strongly electron-donating ligands. Their increased stability allows for the preparation of ruthenium olefin metathesis catalysts that are efficient in both ring-opening and ring-closing reactions
A diversity of recently reported methodology for asymmetric imine reduction
This review contains an account of recent developments in catalytic, asymmetric processes reported for the reduction of C=N bonds to amines, in which we have attempted to communicate the remarkable diversity of methods which have been reported in recent years, including organometallic and organocatalytic processes
Photonic crystal resonator integrated in a microfluidic system
We report on a novel optofluidic system consisting of a silica-based 1D
photonic crystal, integrated planar waveguides and electrically insulated
fluidic channels. An array of pillars in a microfluidic channel designed for
electrochromatography is used as a resonator for on-column label-free
refractive index detection. The resonator was fabricated in a silicon
oxynitride platform, to support electroosmotic flow, and operated at 1.55
microns. Different aqueous solutions of ethanol with refractive indices ranging
from n = 1.3330 to 1.3616 were pumped into the column/resonator and the
transmission spectra were recorded. Linear shifts of the resonant wavelengths
yielded a maximum sensitivity of 480 nm/RIU and a minimum difference of 0.007
RIU was measured
Using computer simulation to improve patient flow at an outpatient internal medicine department
This paper presents the use of discrete-event simulation to support process improvements at an outpatient internal medicine department. This department is significantly effective upon treating patients; however, patient waiting times tend to be longer and consequently patient satisfaction rates continue to decrease. With the aid of this technique, 3 improvement scenarios proposed by medical and administrative staff from this department were designed and simulated including changes related to installed capacity and an emphasis on physicians keeping to the schedule. Statistical analysis of output data evidenced which scenarios resulted in poor performance (statistically equal or higher waiting times) and which strategies caused lower waiting times. In this case, Scenario 3 was selected as the best improvement choice with 71.28 % and 19.28 % reduction in average waiting time and standard deviation respectively. With this approach, inefficient strategies can be avoided and real improvement alternatives can be identified
Identifying the most appropriate classifier for underpinning assistive technology adoption for people with dementia: an integration of Fuzzy AHP and VIKOR methods
Recently, the number of People with Dementia (PwD) has been rising exponentially across the world. The main symptoms that PwD experience include AQ1 impairments of reasoning, memory, and thought. Owing to the burden faced by this chronic condition, Assistive Technology-based solutions (ATS) have been prescribed as a form of treatment. Nevertheless, it is widely acknowledged that low adoption rates of ATS have hampered their benefits within a health and social care context. It is then necessary to effectively discriminate between adopters and non-adopters of such solutions to avoid cost implications, improve the life quality of adopters, and find intervention alternatives for non-adopters. Several classifiers have been proposed as advancement towards the personalisation of self-management interventions for dementia in a scalable way. As multiple algorithms have been developed, an important step in technology adoption is to select the most appropriate classification alternative based on different criteria. This paper presents the integration of Fuzzy AHP (FAHP) and VIKOR to address this challenge. First, FAHP was used to calculate the criteria and sub-criteria weights under uncertainty and then VIKOR was implemented to rank the classifiers. A case study considering a mobile-based self-management and reminding solution for PwD is described to validate the proposed approach. The results revealed that Easiness of interpretation (GW = 0.192) and Handling of missing data (GW = 0.145) were the two most important criteria. Furthermore, SVM (Qj = 1.0) and AB (Qj = 0.891) were concluded to be the most suitable classifiers for supporting ATS adoption in PwD
Comparison of Stance Phase Knee Joint Angles and Moments Using Two Different Surface Marker Representations of the Proximal Shank in Walkers and Runners
Efforts to compare different surface marker configurations in 3-dimensional motion analysis are warranted as more complex and custom marker sets become more common. At the knee, different markers can been used to represent the proximal shank. Often, two anatomical markers are placed over the femoral condyles, with their midpoint defining both the distal thigh and proximal shank segment ends. However, two additional markers placed over the tibial plateaus have been used to define the proximal shank end. For this experiment, simultaneous data for both proximal shank configurations were independently collected at two separate laboratories by different investigators, with one lab capturing a walking population and the other a running population. Common discrete knee joint variables were then compared between marker sets in each population. Using the augmented marker set, peak knee flexion after weight acceptance was less (1.2-1.7°, p<0.02) and peak knee adduction was greater (0.7-1.4°, p<0.001) in both data sets. Similarly, the calculated peak knee flexion moment was less by 15-20% and internal rotation moment was greater by 11-18% (p<0.001). These results suggest that the calculation of knee joint mechanics are influenced by the proximal shank’s segment endpoint definition, independent of dynamic task, investigator, laboratory environment, and population in this study
Wireless connection of bioimpedance measurement circuits based-on AD5933: A state of the art
This contribution describes the state of the art in bioimpedance measurements through development boards to build portable devices that perform in-situ measurements and potential technological opportunities to separate the AD5933 integrated circuit from a PC. The presented research is based on prototypes developed with the aim of achieving portability with the AD5933 integrated circuit and it includes different wireless connection methods and a varied software design for the acquisition, visualization and storage of data obtained from biological systems. As a result, this work describes twenty articles that perform wireless connectivity using different microprocessors for different applications. These references seek to explore technological trends, deficiencies, and opportunities for future development projects in telemedicine.Fil: Dell'osa, Antonio Héctor. Universidad Nacional de Tierra del Fuego. Instituto de Desarrollo Economico E Innovacion; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro Austral de Investigaciones CientÃficas; ArgentinaFil: Apátiga Pérez, D. S.. Instituto Politécnico Nacional. Centro de Investigación y de Estudios Avanzados. Departamento de Investigaciones Educativas.; MéxicoFil: Suárez Pérez, K. I.. Instituto Politécnico Nacional. Centro de Investigación y de Estudios Avanzados. Departamento de Investigaciones Educativas.; MéxicoFil: RamÃrez Barrios, M.. Instituto Politécnico Nacional. Centro de Investigación y de Estudios Avanzados. Departamento de Investigaciones Educativas.; México4th Latin American Conference on Bioimpedance 2021San Luis PotosÃMéxicoSocieda Mexicana de IngenierÃa Biomédic
Agricultural matrices affect ground ant assemblage composition inside forest fragments
© 2018 Assis et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The establishment of agricultural matrices generally involves deforestation, which leads to fragmentation of the remaining forest. This fragmentation can affect forest dynamics both positively and negatively. Since most animal species are affected, certain groups can be used to measure the impact of such fragmentation. This study aimed to measure the impacts of agricultural crops (matrices) on ant communities of adjacent lower montane Atlantic rainforest fragments. We sampled nine forest fragments at locations surrounded by different agricultural matrices, namely: coffee (3 replicates); sugarcane (3); and pasture (3). At each site we installed pitfall traps along a 500 m transect from the interior of the matrix to the interior of the fragment (20 pitfall traps ~25 m apart). Each transect was partitioned into four categories: interior of the matrix; edge of the matrix; edge of the fragment; and interior of the fragment. For each sample site, we measured ant species richness and ant community composition within each transect category. Ant richness and composition differed between fragments and matrices. Each sample location had a specific composition of ants, probably because of the influence of the nature and management of the agricultural matrices. Species composition in the coffee matrix had the highest similarity to its corresponding fragment. The variability in species composition within forest fragments surrounded by pasture was greatest when compared with forest fragments surrounded by sugarcane or, to a lesser extent, coffee. Functional guild composition differed between locations, but the most representative guild was ‘generalist’ both in the agricultural matrices and forest fragments. Our results are important for understanding how agricultural matrices act on ant communities, and also, how these isolated forest fragments could act as an island of biodiversity in an ‘ocean of crops’
Efficacy of eribulin for metastatic breast cancer based on localization of specific secondary metastases: a post hoc analysis
Prior pooled analysis of eribulin studies (301 and 305) indicated eribulin prolonged overall survival (OS) in patients with locally advanced/metastatic breast cancer (MBC) regardless of visceral or nonvisceral disease. This hypothesis-generating post hoc analysis examined the efficacy of eribulin according to the location of metastatic sites at baseline in 1864 pretreated patients with locally advanced/MBC from studies 301 and 305. Analyses included OS, progression-free survival (PFS), and objective response rate; OS and PFS were also analyzed according to estrogen-receptor status. Eribulin appeared efficacious in patients with locally advanced/MBC, irrespective of the location of metastases at baseline. A nominally significant difference in OS in favor of patients randomized to eribulin compared with control in patients with bone, lymph node, and chest wall/breast/skin metastases at baseline was observed. Additionally, a difference in OS was also seen in patients with liver metastases randomized to eribulin versus control (median: 13.4 versus 11.3 months, respectively; hazard ratio, 0.84 [95% CI: 0.72, 0.97]). Results of this exploratory analysis suggest that eribulin may be efficacious for the treatment of locally advanced/MBC for patients with bone, liver, lung, lymph node, and chest wall/breast/skin metastases
Diagnostic accuracy of diabetic retinopathy grading by an artificial intelligence-enabled algorithm compared with a human standard for wide-field true-colour confocal scanning and standard digital retinal images.
Background: Photographic diabetic retinopathy screening requires labour-intensive grading of retinal images by humans. Automated retinal image analysis software (ARIAS) could provide an alternative to human grading. We compare the performance of an ARIAS using true-colour, wide-field confocal scanning images and standard fundus images in the English National Diabetic Eye Screening Programme (NDESP) against human grading.
Methods: Cross-sectional study with consecutive recruitment of patients attending annual diabetic eye screening. Imaging with mydriasis was performed (two-field protocol) with the EIDON platform (CenterVue, Padua, Italy) and standard NDESP cameras. Human grading was carried out according to NDESP protocol. Images were processed by EyeArt V.2.1.0 (Eyenuk Inc, Woodland Hills, California). The reference standard for analysis was the human grade of standard NDESP images.
Results: We included 1257 patients. Sensitivity estimates for retinopathy grades were: EIDON images; 92.27% (95% CI: 88.43% to 94.69%) for any retinopathy, 99% (95% CI: 95.35% to 100%) for vision-threatening retinopathy and 100% (95% CI: 61% to 100%) for proliferative retinopathy. For NDESP images: 92.26% (95% CI: 88.37% to 94.69%) for any retinopathy, 100% (95% CI: 99.53% to 100%) for vision-threatening retinopathy and 100% (95% CI: 61% to 100%) for proliferative retinopathy. One case of vision-threatening retinopathy (R1M1) was missed by the EyeArt when analysing the EIDON images, but identified by the human graders. The EyeArt identified all cases of vision-threatening retinopathy in the standard images.
Conclusion: EyeArt identified diabetic retinopathy in EIDON images with similar sensitivity to standard images in a large-scale screening programme, exceeding the sensitivity threshold recommended for a screening test. Further work to optimise the identification of ‘no retinopathy’ and to understand the differential lesion detection in the two imaging systems would enhance the use of these two innovative technologies in a diabetic retinopathy screening setting
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